Rotax PTO Taper?

Armilite

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Joined
Sep 5, 2011
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Location
AMES, IA USA
Rotax used mainly 30mm 1:10 PTO Taper for most of its 2 Strokes. The 670 and Newer Engines use a 33mm 1:7.5 PTO Taper. Now I have had a lathe for 25+ years and never did a Taper. I have a Steel Pulley that has a Straight Hole and I want to fit on my 277 PTO, but I don't have a 277 PTO Drawing. I'm wondering if I can just buy a 30mm 1:10 Reamer and Drill Bit to do this.

I found this Taper Calc. Under 10% they show 1:10 = 5° 43'. On the drawing, they show Big End as 29mm/1.141729" OD, and Flute Lenght 19.5mm/0.7677142" which Calc shows end as 27.05mm/1.064957"
http://www.magafor.com/841/uk.htm

So am I Thinking right? Do I look for a 30mm 1:10 Taper Reamer or a 29mm 1:10 Taper Reamer? The Steel Pulley Hole Mic's out at 22.16mm so to Ream it, I probably should drill it closer to just under 27mm. I want to practice on some Scrap Aluminum Stock first. The Pulley has a depression on the front and an extension on the Back, front to back is about 35mm.

Here is a 503 PTO Spec's.
Rotax 503 PTO.jpg Rotax Taper 30mm 1_10.jpg Tapers.jpg

Bought 8 Groove Diesel Truck Alternator Serpentine Belt Pulley 2.37O.D .875  ID - 3.jpg
 
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